The present invention relates to bearings, and more particularly to a lightweight, flanged bearing ring for the hub of a motor vehicle wheel.
The bearing ring of a typical wheel hub bearing assembly may either be a stationary ring with a flange for mounting the relevant hub-bearing unit to the suspension standard of a motor vehicle, or a rotatable ring where the flange provides connection to the wheel and/or the brake rotor.
There is an ever increasing demand for weight reduction in motor vehicle components for in order to lower fuel consumption and exhaust emissions. With a vehicle wheel bearing, weight reduction must not result in a reduction in strength and/or safety. The raceways must be made of a material of hardness sufficient to resist the stresses of rolling contact. Conventional bearing steel is still widely used, although other materials have been proposed, such as ceramics and titanium, which provide good mechanical performance but are considerably more expensive as compared to bearing steel.
WO 2008/147284 A1 discloses a bearing ring made up of two different materials joined together in a single piece, namely a first, high toughness material such as bearing steel forming the raceways and a second, lightweight material, such as a lightweight metal, forming the rest of the ring. The second material is joined to the first material by a semi-solid casting process.